This report documents the establishment of a study to determine the effect of thinning on incidence of mountain pine beetle, Dendroctonus ponderosae Hopk., infestation in second-growth ponderosa pine stands in western Montana.
Although insufficient time has passed for a similar study in Oregon to yield a solid base for a...
Epidemic levels of the pine butterfly, Neophasia menapia (Felder and
Felder) have been evident in ponderosa pine stands in the Bitter Root
Valley since 1969. Evaluations of this infestation were initiated in
1970 to assess overwintering egg populations at 20 locations within
the infestation (Ciesla et al. 1971). Defoliation was...
The pine butterfly, Neophasia menapia (Felder and Felder), infestation on the Nezperce National Forest was aerially surveyed in mid-August 1972.
A followup ground evaluation was made in September. Results of the survey
show the infestation has increased substantially in intensity and size.
The infestation was first reported in 1971 when...
Many nonmerchantable trees on the proposed control areas are moderately to heavily infested with dwarf mistletoe. Control by sanitation-thinning is desirable and is both biologically and economically sound.
The larch casebearer Coleophora laricella (Hbn.) is now established throughout all western larch stands in Region 1. Population levels have begun to fluctuate in some of the older infested stands; however, it is still on the increase in more recently invaded territory. During the past 2 years work was begun...
The mountain pine beetle, Dendroctonus ponderosas Hopk., showed a significant advance northward from the 1970 infestation boundary, encompassing almost one-third of the total Park acreage. A fall survey conducted in the Park showed an average of 71.1 trees per acre with red or fading foliage from previous year's attacks and...